Whooping cough (pertussis) is a highly contagious infection of the upper respiratory tract that causes inflammation of the breathing passages and episodes of intense coughing. During the first two weeks of this infection, symptoms may resemble those of a cold, asthma or allergy (e.g., coughing, sneezing). During a pertussis-related coughing fit, coughing can become so intense, and breathing so difficult, that a person ends up gasping for breath after it finally subsides. The effort to get air in quickly through narrowed airway passages produces the characteristic “whooping” sound that gives the infection its distinctive name.
Whooping cough primarily affects children, but also can afflict teens and adults. Since the 1940s, infants born in the United States have had access to the DTP vaccine, which immunizes them against whooping cough (as well as tetanus and diphtheria). As a result, the spread of whooping cough has been largely contained in recent decades, according to the U.S. Centers for Disease Control and Prevention (CDC). However, the 1980s and 1990s saw a rise in the number of new infections. Many of those becoming infected are infants younger than 6 months old, when most children are still not fully vaccinated against whooping cough in the United States. Whooping cough is more common in females than males.
Healthcare experts stress that vaccinations remain the best way to prevent whooping cough. Over time, the vaccine itself wears off, and a person becomes less protected from the infection, although booster shots are now available for adolescents and adults. Teens and adults who get the whooping cough infection tend to have far milder symptoms than infants and children. The CDC recommends booster shots for teens and adults.
About whooping cough
Whooping cough (pertussis) is an upper respiratory infection caused by Bordetella pertussis bacteria. These bacteria live in the saliva and nasal mucus of an infected person. People become infected by inhaling tiny, contaminated droplets from the sneeze or cough of an already infected person.
Once inside the body, pertussis bacteria produce toxins that prevent the respiratory tract from eliminating germs. The bacteria also create chemicals that cause inflammation and damage the lining of breathing passages, specifically the nasopharynx, which is where the nasal passages meet the back of the throat.
People with whooping cough have fits of violent coughing that can leave them gasping for breath. The attempt to inhale quickly through narrowed breathing passages causes the typical, high-pitched “whooping” sound that gives the infection its common name. It appears that the coughing itself is the result of trying to expel thick mucus from the lungs and throat.
Complications of whooping cough may include seizures, stopped breathing (apnea), ear infections and brain damage. In rare cases, whooping cough can be fatal, especially for infants. Secondary bacterial pneumonia is the major cause of these deaths.
Before the vaccine became available, more than 200,000 cases of whooping cough were reported each year, according to the U.S. Centers for Disease Control and Prevention (CDC). Today, that number has been reduced to about 5,000 to 7,000 cases annually.
In the past two decades, there has been a steady increase in the number of new cases of whooping cough, with cyclical spikes every three to five years. Most of these new cases occur in children younger than 6 months, who are not yet fully immunized against the infection. Some physicians are urging new research that will allow earlier vaccinations to protect infants.
In many cases, teens and adults are responsible for spreading whooping cough to children. The vaccine that prevents whooping cough during childhood usually wears off by early adulthood. As a result, college campuses and nursing homes have become fertile ground for outbreaks of whooping cough, which is then spread to infants who are not yet fully immunized.
Signs and symptoms of whooping cough
Whooping cough symptoms can appear from three to 21 days after exposure to the infection. During the first two weeks the symptoms may resemble those of colds, asthma or allergies, so these conditions will need to be ruled out by a physician. Whooping cough infection generally has three stages that unfold over six to 10 weeks or longer. Symptoms are generally milder for teens and adults. Symptoms tend to be worse for children and those who never have been vaccinated for whooping cough.
The first stage (catarrhal) begins within days or weeks after infection and lasts from several days to two weeks. An infected person is most contagious during the first stage of the infection. Symptoms during this phase resemble those of a common cold or allergy and include:
Sneezing
Runny nose
Nasal congestion
Mild, dry coughing
Watery eyes
Mild fever
In babies, the following symptoms may also be present:
Bluish or pale complexion
Bulging or watery eyes
Arms and legs flailing in distress
Tendency to stick out tongue or push chest forward
During the second stage (paroxysmal), early symptoms fade, but are replaced by waves of violent, wet coughing fits that bring up mucus. These episodes are so intense that breathing during them may be nearly impossible. When the cough finally subsides, the person is likely to gasp for breath. As air rushes into the body through narrowed airways, a “whooping” sound may follow.
Some of the symptoms of the second stage include:
Wet coughing spells of a minute or longer, 15 to 24 times in a 24–hour period
Attacks that occur more often at night
Patient turning red from effort, or blue from cyanosis (lack of oxygen)
Vomiting and severe exhaustion after coughing spells
Tiny, red spots (petechiae) on the skin of the upper body due to blood–vessel ruptures
Small areas of bleeding in the whites of the eyes
Ribs bruised or broken during intense coughing
The paroxysmal stage is the most serious stage of whooping cough, and it lasts for one to six weeks or longer. Between coughing spells, a person may appear healthy. In addition, infants may not make the “whooping” noise usually associated with the second stage. Infants with whooping cough have an increased risk for pneumonia.
During the third stage (convalescent), the coughing often becomes louder, but the patient improves and becomes stronger. Coughing spells continue to flare up sporadically, especially if the patient has a cold or other respiratory illness. The third stage lasts two weeks or longer.
Diagnosis methods for whooping cough
Diagnosing whooping cough can be difficult, because an infected person often appears healthy between coughing fits. A healthcare provider may suspect whooping cough if there has been a recent outbreak in the community, or if symptoms of other respiratory disorders that feature a cough, such as bronchitis or a cold, are not present.
To rule out other diseases, a physician may order:
Complete blood count. A blood test that provides a basic evaluation of the cellular components in blood. Included are the number of blood cells and platelets, the percentage of each type of white blood cell and hemoglobin content. The size and shape of red blood cells also can be determined.
Chest x-rays. These provide a good outline of the heart and major blood vessels. They can usually reveal serious diseases of the lungs.
Pulse oximeter. A small probe is placed on the ear or finger to measure the amount of oxygen in the blood. This painless procedure allows physicians to determine blood oxygen levels without drawing blood.
A test of mucus in the nasopharynx (back of the throat) can reveal if Bordetella pertussis bacteria are present. Because it can take two weeks before results come back, a physician often will start treatment immediately if whooping cough is strongly suspected.
Treatment options for whooping cough
Antibiotics are the primary treatment for whooping cough. These can help shorten the length of the illness, but are prescribed primarily to reduce the spread of infection. Because of the contagious nature of this condition, family members might be encouraged to also take antibiotics, even before they display any symptoms. The U.S. Centers for Disease Control and Prevention estimates that 80 percent to 90 percent of those who live with an infected person will become infected as well.
To be effective, antibiotics must be taken according to a physician’s schedule. They must also be taken for the full course of treatment, despite an improvement of symptoms.
Infants less than 6 months old with suspected cases of whooping cough are likely to be hospitalized for monitoring and to ensure they are getting enough fluids and nutrients and are able to handle coughing episodes. In some cases, mucus may be suctioned from the nose and throat of babies and oxygen therapy may be recommended.
Physicians sometimes will prescribe corticosteroids (anti-inflammatory drugs) or bronchodilators (which open airways) to reduce the severity and duration of coughing spells.
Individuals with whooping cough and others around them should frequently wash their hands to reduce the spread of the infection. Patients or those caring for children with whooping cough can take the following steps to reduce the discomfort brought on by symptoms:
Reduce exposure to dust, smoke and changes in temperature.
Maintain a calm atmosphere to minimize stimulation, which can provoke coughing spells. Try not to introduce sudden noises or lights.
Ensure adequate nutrition and hydration. Fluids and nutritious foods can help keep a patient from becoming exhausted after grueling coughing fits. They also prevent dehydration and replace lost nutrients after vomiting.
Run a cool-mist humidifier. Dry, hot air can worsen coughing spells, while the cooler, misty air loosens respiratory secretions and soothes irritated airways. In some cases, humidity may worsen symptoms. If this occurs, discontinue humidifier use.
Prevention methods for whooping cough
Without question, the best way to prevent whooping cough is through immunization. The vaccine for whooping cough is extremely effective and generally has few side effects. Potential side effects include soreness at the injection site, mild to moderate fever and irritability.
Today, virtually every infant in the United States is immunized with the DTP vaccine, or its new variant, DTaP. This vaccine is provided to infants at 2, 4 and 6 months of age and provides immunization against diphtheria, tetanus and pertussis. Booster shots often are given at 1 year, 18 months of age and between the ages of 4 and 6. The vaccine may also be combined with other childhood immunizations, in which case the schedule may vary.
DTaP is a modified version of the DTP vaccine that removes the part of the bacteria that causes fever and irritability. As a result, it has even fewer side effects than DTP, though it is not as widely used due to its greater cost. In very rare instances, both of these vaccines can cause an allergic reaction or acute, severe central nervous system disorder. An allergic reaction will occur within minutes to hours of vaccination.
Teenagers and adults do not routinely receive booster shots of the whooping cough vaccine. However, recent studies suggest that such vaccination could reduce the number of infections and prevent the disease from spreading to infants.
Previously, there was no pertussis-containing vaccine licensed for people 7 years of age or older. However, in 2005, a booster vaccine (Tdap) was made available for adolescents and adults. The U.S. Centers for Disease Control and Prevention advises that all adolescents over the age of 11 receive a booster shot of Tdap, although they are encouraged to wait at least five years after they receive the Td (tetanus) booster vaccination. Healthcare workers and those who expect to come into contact with infants should also receive the Tdap booster. Pregnant women are advised to consult their physician about the suitability of the Tdap booster during pregnancy. Women may be advised to receive the Tdap booster shortly after childbirth. The booster may also be recommended for other adults in close proximity to infants, such as fathers, grandparents and child care workers.
Questions for your doctor
Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about whooping cough:
Do my symptoms indicate whooping cough?
What methods will you use to determine if I have whooping cough?
What are my treatment options?
When can I expect my symptoms to improve?
Is it safe to be around my child?
How can I prevent spread of whooping cough within my family?
Should my family members take antibiotics as a preventive measure?
Does this condition pose a danger to my overall health?
